1. Field of the Invention
The present invention relates to an oven provided in an aircraft.
2. Description of the Related Art
The galley unit provided in an aircraft includes a cabinet formed for example of honeycomb panels and various cooking equipments stored inside the cabinet.
Japanese Patent Application Laid-Open Publication No. 2001-199399 (patent document 1) discloses one example of a structure of a galley unit, and Japanese PCT Application Laid-Open Publication No. 2002-502649 (patent document 2) discloses a beverage cooking equipment provided inside the galley unit.
The power supplied to the galley unit from the aircraft is generally fed from an alternating-current (AC) power supply with a fixed cycle (for example, 400 Hz). However, there are plans to use a variable AC power supply with a frequency range of 360 Hz through 800 Hz, for example, in aircrafts to be developed in the future.
There are various equipments provided inside the galley unit including an oven unit for cooking, which is equipped with a fan for circulating the heat and moisture inside the unit and a motor for driving the fan.
Therefore, the oven unit requires a device for converting the frequency of the AC power being fed thereto in order to maintain the desirable motor rotation.
The galley unit is formed of panel members, and includes a compartment for storing a plurality of service carts and a space to which a plurality of oven units are arranged.
If all the fan motors equipped in the multiple oven units arranged in the galley rotate at uniform speed, the motors generate a so-called beating noise.
This beating noise is amplified into a very loud noise by the compartment housing the service carts functioning as a speaker box.
Galley units are usually placed close to passenger seats, and such loud noise will annoy the passengers, causing deterioration of the service provided to the passengers on the aircraft.